Phenotypic plasticity: a brief introduction. Phenotypic plasticity describes the ability of a given genotype to produce different phenotypes in response to distinct environmental conditions. It has major implications in agronomy, animal husbandry and medicine and is also thought to facilitate evolution. Phenotypic plasticity is widely observed in the wild. It is only relatively recently that the mechanisms involved in phenotypic plasticity have been analysed. Thanks to laboratory experiments we understand better how environmental conditions are involved in phenotypic variations. This article introduces major concepts from the phenotypic plasticity field, presents briefly mechanisms involved in phenotypic plasticity and discusses the links between phenotypic plasticity and evolution.